ISM6636A&B_Rev1.10解密.pdf - 第29页
29 Innovision Semiconductor Preliminary Datas heet ISM6636 A/B Rev1.10 01/2023 EN pin I2C ENABLE Soft S top E nable Soft S top P ower down State 0x1B[0] 0x14[2] 0x1C[3] 0 0 \ \ Power Off 1 0 \ \ 0 1 \ \ 1 1 0 0 Power On …
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Innovision Semiconductor
Preliminary Datasheet
ISM6636A/B
Rev1.10 01/2023
Table 18 Register = 0x13
The setting of the output voltage needs to be determined according to the loop conditions.
The suffixes of ISM6636A\B are different, corresponding to the different inductance values.
It is recommended that when using this function, the voltage adjustment range should not
exceed 20% of the default setting and follow the above programming principles.
Register = 0x14 Soft Start and Switch Mode
Register = 0x1B I2C start (I2C Enable)
Register = 0x1C Soft Stop Power down
These three register addresses are related to the power-off and startup mode of the
ISM6636X.
ISM6636X supports soft start (Soft Start) and soft shutdown (Soft Stop) time rate adjustable.
When the VCC voltage exceeds the undervoltage protection value, the internal soft start
(Soft Start) circuit will work, and the output voltage will rise to the target voltage at the rate
set by register 0x14. The target voltage is determined by registers 0x12 and 0x13. During
the soft-start, the over-current protection (OC) and over-voltage protection (OV) functions
are enabled to ensure that the module is fully protected. The soft start register (Soft Start)
0x14 has a total of 4 settings, which are as follows:
For ISM6636A/B-xxxx,
[4:3]=00 : 1mV/µs; [4:3]=01 : 2mV/µs; [4:3]=10 : 0.5mV/µs; [4:3]=11 : 4mV/µs;
The Soft Stop rate is the same as the Soft Start rate and cannot be set independently. If
you want to implement the Soft Stop function, it can only be realized through the register
0x14 Bit[2] and register 0x1C Bit[3] via I2C. The module does not support the EN pin control
soft stop (Soft Stop) function. Shutdown (Soft Stop) is off by default.
The startup and shutdown of the module are realized by the external EN pin and the three
internal registers. The specifics can be referred to the following table:
Command
Vout_Low_Byte
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Function
Set Vout voltage.
Default
Default
Default
Default
Default
Default
Default
Default
Default
29
Innovision Semiconductor
Preliminary Datasheet
ISM6636A/B
Rev1.10 01/2023
EN pin
I2C ENABLE
Soft Stop Enable
Soft Stop Power down
State
0x1B[0]
0x14[2]
0x1C[3]
0
0
\
\
Power Off
1
0
\
\
0
1
\
\
1
1
0
0
Power On
1
1
0
1
1
1
1
0
1
1
1
1
Soft Stop Power down
Table 19 Start and power off (“\” means ignore the state of this register)
ISM6636X supports forced continuous mode and discontinuous conduction mode (FCCM
and DCM), which can be set through register 0x14 Bit [1]. The rules are as follows:
•
When 0x14 Bit[1] = 0, the module will be in forced continuous mode (FCCM).
• When 0x14 Bit[1] = 1 and EN pin input voltage is lower than 2.5V, the module will be in
discontinuous conduction mode (DCM).
• When 0x14 Bit[1] = 1 and EN pin input voltage is higher than 2.5V, the module will be
in forced continuous mode (FCCM).
Command
Soft Start and Switch Mode
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R
R
R
R/W
R/W
R/W
R/W
R
Function
no use
Soft Start_Rate
Soft Stop Enable
FCCM and DCM
no use
Default
0
0
0
0
0
0
1
0
Table 20 Register = 0x14
Command
I2C Enable
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R
R
R
R
R
R
R
R/W
Function
no use
I2C Enable
Default
0
0
0
0
0
0
0
0
Table 21 Register = 0x1B
Command
Soft Stop Power down
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R
R
R
R
R/W
R
R
R
Function
no use
Soft Stop Power down
no use
Default
0
0
0
0
0
0
0
0
Table 22 Register = 0x1C
30
Innovision Semiconductor
Preliminary Datasheet
ISM6636A/B
Rev1.10 01/2023
Register = 0x17 Overvoltage protection threshold setting
(OV_Threshold)
The overvoltage protection function is realized by monitoring the voltage of the VOS pin.
The module will compare the voltage collected by VOS with the set voltage. When the VOS
voltage exceeds the output overvoltage protection threshold (OV) for 5us, over voltage
protection will kick in, and the high side FET will no longer be turned on. And when it is
detected that the current of the low side FET dips below 0A, it enters a tri-state. The
overvoltage protection thresholds are set as follows:
[1:0]=00 : 105%; [1:0]=01 : 110%; [1:0]=10 : 115%; [1:0]=11 : 120%;
Command
OV_Threshold
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R
R
R
R
R
R
R/W
R/W
Function
no use
OV_Threshold
Default
0
0
0
0
0
0
1
1
Table 23 Register = 0x17
Register = 0x18 Power Indication Threshold (PG_Threshold)
The power indicator function will be turned on after the soft start (Soft Start), and the PG will
be in a de-asserted state before the soft start (Soft Start). This function is judged by the
VOS monitoring voltage. When the voltage collected by VOS is above the power indication
threshold, the PG signal will be pulled high. When the voltage collected by VOS is 5% lower
than the power indication threshold, the PG signal will be pulled low.
[1:0]=00 : 80%; [1:0]=01 : 85%; [1:0]=10 : 90%; [1:0]=11 : 95%;
Command
PG_Threshold
Format
unsigned binary
Bit
7
6
5
4
3
2
1
0
Access
R
R
R
R
R
R
R/W
R/W
Function
no use
PG_Threshold
Default
0
0
0
0
0
0
1
0
Table 24 Register = 0x18
Register = 0x19 Over-temperature protection threshold setting
(OT_Threshold)
The ISM6636X provides an adjustable over-temperature protection threshold setting
function. When the module temperature exceeds the temperature setting threshold, the
module will stop turning on the high side FET and reset the internal soft-start time. At this
point the internal LDO is still running. When the detected temperature drops to a working
range, the module will automatically restart. The hysteresis of over temperature protection
is about 20°C or so. The threshold settings for over temperature protection are as follows.
[1:0]=00 : 75°C; [1:0]=01 : 85°C; [1:0]=10 : 125°C; [1:0]=11 : 145°C;